Cullimore, A.M.; Finnie, J.W.; Marmion, W.J.; Booth, T.M. Equine Veterinary Education May 2009 21 5 247-251(5) A 3-year-old filly was presented for severe lameness referable to the left front fetlock joint. Radiographs confirmed an osseous cyst-like lesion and synovial fluid cytology ruled out sepsis. The filly responded poorly to medical management and was subsequently subjected to euthanasia. Post mortem examination confirmed an impact fracture of the proximal phalanx, previously undiagnosed in the horse.